Using Command As New OleDbCommand("select * from stunden WHERE [DATUM]= ? order" & _
  " by DOKNR DESC", con)
       Command.Parameters.Add("Suchdatum", OleDbType.Date)
       Command.Parameters("Suchdatum").Value = CDate(Suchtext)
       using da as new OleDbDataAdapter(Command)
          da.Fill(dt)
       End Using
 End Using